a. Field of Invention
This invention relates to novel processes for the production of N-(2-alkoxy-1-naphthoyl)glycine esters. The N-(2-alkoxy-1-naphthoyl)glycine esters produced by the present process are themselves useful intermediates for the manufacture of N-naphthoylglycine derivatives having aldose reductase inhibiting activity and which are useful for treating diabetic complications. Said aldose reductase inhibitors are described in copending patent application Ser. No. 397623, incorporated herein by reference.
More specifically this invention relates to the process for the production of N-[[2-alkoxy-6-methoxy-5-(trifluoromethyl)-1-naphthalenyl]carbonyl]-N-meth ylglycine esters of formula (I) ##STR1## wherein R.sup.1 and R.sup.2 are lower alkyl or aryl(lower)alkyl, wherein lower alkyl contains 1 to 6 carbon atoms.
b. Prior Art
The closest prior art to the present invention is Sestanj et al, U.S. Pat. No. 4,439,617, Mar. 27, 1984; and Sestanj et al, U.S. Pat. No. 4,568,693, Feb. 4, 1986. Sestanj et al disclosed processes for preparing N-naphthoylglycine esters which are intermediates in the preparation of compounds which inhibit aldose reductase, but which lack a 2-alkoxy substituent on the naphthalene ring.